Right. You file each year separately like normal. Any state refunds you get you will report in the year you actually get the refund so if you get them in 2021, they will go on your 2021 federal return you file in 2022.
You do not report federal refunds. I don't understand your question about money coming back.
Each tax year is a separate return. Each one must be prepared using the forms and software for the specific tax year. You cannot combine them in ANY way---not even by mailing them in the same envelope.
The online software program is for 2020----no other year. Do not try to use online for any of your past year returns. It sounds like you are going to need to purchase several tax prep programs.
Online preparation and e-filing for 2017, 2018 and 2019 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2017, 2018, or 2019 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Federal and state returns must be in separate envelopes and they are mailed to different addresses. Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.
If you are getting a refund, there is not a penalty for filing past the deadline. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
No federal refunds from any prior tax year are entered on a 2020 federal tax return.
Each prior year tax return is completed individually. When mailing the tax returns use separate envelopes for each tax year.
Note that tax refunds will only be returned if filed within three years from the due date of the original tax return. For example, tax year 2017 must be filed on or before April 15, 2021 for a tax refund. Tax returns prior to 2017 with tax refunds will be processed but no refund will be returned.
To complete and file prior year tax returns, 2019 thru 2017, using TurboTax you would need to purchase, download and install on a personal computer one of the desktop editions for each tax year required from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A prior year tax return can only be printed and mailed, it cannot be e-filed.